A typical bottom-gate staggered thin film transistor can be fabricated by some of the following steps: forming a gate conductor on an upper surface of a transparent substrate; depositing a gate dielectric layer over the gate conductor; depositing a layer of amorphous silicon over the gate dielectric layer; depositing a layer of n+ doped amorphous silicon over the amorphous silicon layer; depositing a layer of source/drain metallization over the n+ doped silicon layer; and patterning the source/drain metallization layer and optionally one or more underlying layers to form respective source and drain electrodes.
Low-resistance TFT metallizations are used e.g. in the manufacture of LCDs for improving the picture quality, the power consumption of the LCDs, and the production cost. For instance copper (Cu), due to its reliability against electromigration and hillock formation, is one of the candidates for replacing aluminum generally used for metallizations.